In the healthcare industry, nursing robots have made great contributions, assisting in the delivery of food and medicine as well as the movement and transfer of patients. However, the traditional continuum manipulator often has the problems of limited workspace and weak carrying capacity. Compared with traditional manipulator, the continuum manipulator has the advantages of a small moment of inertia and high dexterity. This paper proposes a original cable-driven parallel continuum manipulator with a spherical parallel mechanism as the continuous segments. Due to the spherical parallel mechanisms’ characteristics, the proposed cable-driven spherical parallel continuum manipulator offers many inherent advantages for nursing robots. The prototype is tested and analyzed, and the kinematics and statics are verified. The results show that the cable-driven spherical parallel continuum manipulator for nursing robots has low requirements for workspace, suitable for complex spaces and can have a large carrying capacity.

In mobile networks, distance variations caused by node mobility generate fluctuations in the channel gains. Such fluctuations can be treated as another type of fading besides multipath effects. In this paper, the interference statistics in mobile random networks are characterized by incorporating the distance variations of mobile nodes to the channel gain fluctuations. The mean interference is calculated at the origin and at the border of a finite mobile network. The network performance is evaluated in terms of the outage probability. Compared to a static network, the interference in a single snapshot does not change under uniform mobility models. However, random waypoint mobility increases (decreases) the interference at the origin (at the border). Furthermore, due to the correlation of the node locations, the interference and outage are temporally and spatially correlated. We quantify the temporal correlation of the interference and outage in mobile Poisson networks in terms of the correlation coefficient and conditional outage probability, respectively. The results show that it is essential that routing, MAC, and retransmission schemes need to be smart (i.e., correlation-aware) to avoid bursts of transmission failures.

For communication between two neighboring nodes in wireless networks, the local delay is defined as the time it takes a node to successfully transmit a packet. Previous research focuses on the local delay in static or infinitely mobile Poisson networks with ALOHA. In this paper, we extend the local delay results to Poisson networks with finite mobility. The results obtained show that mobility helps reduce the local delay. Bounds of the local delay in mobile Poisson networks are derived for different mobility and transmission models. The phase transition that marks the jump of the local delay from finite to infinite is also characterized.

We design and implement a software-radio system for Superposition Coding (SC), a multiuser transmission scheme that deliberately introduces interference among user signals at the transmitter, using a library of off-the-shelf point-to-point channel codes. We experimentally determine the set of rate-pairs achieved by this transmission scheme under a packet-error constraint. Our results suggest that SC can provide substantial gains in spectral efficiencies over those achieved by orthogonal schemes such as Time Division Multiplexing. Our findings also question the practical utility of the Gaussian approximation for the inter-user interference in Superposition-Coded systems.

In wireless networks, interference that is generated by undesired transmitters dominantly limits network performance. The correlation of node locations (in mobile or static networks) makes the interference temporally correlated. Such correlation affects network performance greatly, and hence needs to be quantified. In this paper, we quantify the temporal correlation of the interference in mobile Poisson networks. More specifically, we obtain closed-form expressions for the interference correlation coefficient ρ in Poisson line networks under various mobility models. When the mean speed of nodes v̅ increases, we show that ρ is asymptotically proportional to v̅-1. Moreover, multi-path fading and random MAC schemes reduce the temporal correlation of the interference. These results are extended to higher-dimensional networks.

In wireless networks, distance variations caused by node mobility generate fluctuations of the channel gains. Such fluctuations can be treated as another type of fading besides multi-path effects. In this paper, we characterize the interference statistics in mobile random networks by mapping the distance variations of mobile nodes to the channel gain fluctuations. Network performance is evaluated in terms of the outage probability. A nearest-interferer approximation is employed. This approximation provides a tight lower bound on the outage probability. Comparing to a static network, we show that the interference distribution does not change under high mobility and random walk models, but random waypoint mobility increases interference.

Superposition coding is a well-known capacity-achieving coding scheme for stochastically degraded broadcast channels. Although well-studied in theory, it is important to understand issues that arise when implementing this scheme in a practical setting. In this paper, we present a software-radio based design of a superposition coding system on the GNU Radio platform with the Universal Software Radio Peripheral acting as the transceiver frontend. We also study the packet error performance and discuss some issues that arise in its implementation.